I don't think having extensive tests makes it possible to change anything. Much of the work of a programmer is splitting up problems in to chunks that can easi

I don't think having extensive tests makes it possible to change anything. Much of the work of a programmer is splitting up problems in to chunks that can easily fit into our very limited bulbs. This article highlights that there are two aspects to this; one is the one widely known, which is using appropriate abstractions to reduce complexity of any isolated part of the program; but the other part is keeping the changes at a manageable scale. To me this sounds like a very valid and potentially underapprechiated part of working on code with other people involved.